Composite parts may be manufactured by laying up fiber reinforced composite plies on a tool either by hand or using automated fiber placement equipment. A vacuum bag may be placed over the layup and sealed to the tool. The part may then be cured, often by placing the layup in an autoclave where it is subjected to heat and pressure. During curing, a vacuum in the bag may help remove entrapped air and volatiles from the layup.
During the vacuum bagging process, edge breather materials may be placed adjacent or over the edges of the layup which allow the edges to “breathe” before and during curing. The breather materials maintain a volume of space around the edges of the layup so that the entrapped air and volatiles may escape the layup and be drawn away from the bag by the applied vacuum.
The breather materials may comprise, without limitation, non-woven nylon and polyester mats, woven fiberglass, as well as metal chains, braids and meshes. These types of breather materials may not be suited for re-use, and therefore may require replacement each time a layup is cured. The consumable nature of such breathers may render them costly to use in terms of both materials and the labor required to replace them after each cure cycle. Also, consumable types of breather materials may sometimes partially compress or collapse under the force applied by the bag, thereby reducing the volume of space around the edges of the layup which may in turn reduce the ability of the edges to breathe.
Accordingly, there is a need for an edge breather that eliminates the need for consumable breather materials while providing a relatively large and consistent volume of space around the edges of the layup that may aid in evacuating air and volatiles from the layup during curing.